Background: Induction of immunogenic cell death (ICD) in tumors can enhance antitumor immunity and modulate immunosuppression in the tumor microenvironment (TME). Objective: In the current study, we investigated the effect of silibinin, a natural compound with anticancer activity, and its polymer-based nanoformulations on the induction of apoptosis and ICD in cancer cells. Methods: Free and nanoparticulate silibinin were evaluated for their growth-inhibitory effects using an MTT assay. Annexin V/PI staining was used to analyze apoptosis. Calreticulin (CRT) expression was measured by flow cytometry. Western blotting was conducted to examine the levels of elf2α, which plays a role in the ICD pathway. The HSP90 and ATP levels were determined using specific detection kits. Results: Compared to the free drug, silibinin-loaded nanocarriers significantly increased the induction of apoptosis and ICD in B16F10 cells. ICD induction was characterized by significantly increased levels of ICD biomarkers, including CRT, HSP90, and ATP. We also observed an increased expression of p-elf-2α/ elf-2α in B16F10 cells treated with silibinin-loaded micelles compared to cells that received free silibinin Conclusion: Our findings showed that the encapsulation of silibinin in polymeric nanocarriers can potentiate the effects of this drug on the induction of apoptosis and ICD in B16F10 melanoma cells.

中文翻译：

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纳米递送水飞蓟宾可增强黑色素瘤细胞中免疫原性细胞死亡 (ICD) 的诱导

背景：诱导肿瘤中的免疫原性细胞死亡（ICD）可以增强抗肿瘤免疫力并调节肿瘤微环境（TME）中的免疫抑制。目的：在本研究中，我们研究了具有抗癌活性的天然化合物水飞蓟宾及其聚合物纳米制剂对诱导癌细胞凋亡和ICD的作用。方法：使用 MTT 测定评估游离水飞蓟宾和纳米颗粒水飞蓟宾的生长抑制作用。膜联蛋白V/PI染色用于分析细胞凋亡。通过流式细胞术测量钙网蛋白（CRT）表达。进行蛋白质印迹来检查 elf2α 的水平，它在 ICD 途径中发挥作用。使用特定检测试剂盒测定 HSP90 和 ATP 水平。结果：与游离药物相比，负载水飞蓟宾的纳米载体显着增加了 B16F10 细胞凋亡和 ICD 的诱导。ICD 诱导的特点是 ICD 生物标志物水平显着升高，包括 CRT、HSP90 和 ATP。我们还观察到，与接受游离水飞蓟宾的细胞相比，用负载水飞蓟宾的胶束处理的 B16F10 细胞中 p-elf-2α/ elf-2α 的表达增加 结论：我们的研究结果表明，将水飞蓟宾封装在聚合物纳米载体中可以增强水飞蓟宾的作用该药物可诱导 B16F10 黑色素瘤细胞凋亡和 ICD。